It is well known in the prior art how to package items that are initially frozen in order to transport the items from one place to another while maintaining the item in a frozen state during transportation. It is also well known in the prior art how to package and transport items that may be maintained at any ambient temperature during transportation without damage to the item being transported.
However, there has long been a need to develop a method of and apparatus for packaging a temperature sensitive material for transportation. A temperature sensitive material is one which must be packaged in such a way so as to maintain the temperature sensitive material at a predetermined temperature. In the present invention, the temperature sensitive material is one which must be maintained in a cool state, particularly in the temperature range of approximately 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.), during the transportation of the temperature sensitive material from one place to another.
It is often extremely important that a packaging system containing temperature sensitive materials keep the temperature sensitive materials in the range of temperatures of between 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) even if the outside ambient air temperatures to which the package is exposed reach somewhat extreme high or low temperatures. However, once the package leaves the control of the person who is shipping it, the package may be exposed to extremely high and low ambient air temperature.
For instance, a package shipped to northern climate in the winter months or to a southern climate in the summer months may be subjected to somewhat extreme cold or hot temperatures, respectively, for several hours. This could damage the temperature sensitive materials inside the package if the packaging system is incapable of keeping the temperature sensitive materials at an appropriate temperature despite the ambient extreme.
Another scenario, having potentially damaging effects to the temperature sensitive materials within the package, is if the package were placed in a freezer or hot room or vehicle trunk by the shipper, i.e., United Parcel Service ("UPS"), Federal Express, etc. during the transportation of the package from one location to another.
In either case, it is important that once the package carrying the temperature sensitive materials leaves the control of the person or company sending the package, the package be able to maintain the temperature sensitive materials at a temperature in the range of 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) even if the ambient temperature of the air surrounding the package reaches somewhat extreme high or low temperature for several hours.
The packaging and transportation of temperature sensitive materials has become especially important in the new and emerging fields of biotechnology. Indeed, recent biotechnological advances have been developed in which living cells can be taken from a tissue specimen in order for such cells to be transported to laboratories for experimental testing of new pharmaceuticals.
For such uses, the living cells must me kept alive which necessitates keeping the living cells cooled to a temperature of approximately 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) during transportation. At the same time, however, it is very important that the living cells be protected against freezing temperatures because freezing of the cells could cause irreversible damage thus, render them unsuitable for use in experimental testing.
Prior art devices, such as those described in U.S. Pat. No. 4,958,506 to Gullhem et al. and U.S. Pat. No. 4,530,816 to Douglas-Hamilton, disclose containers having water and ice based cooling systems which use a frozen component as the only component of the cooling mechanism.
In particular, the Guilhem et al. patent discloses an isothermic container for transporting grafts at a constant temperature equal to 4.degree. C. (39.degree. F.). The container of the Guilhem et al. patent includes a vessel and removable lid each of which has an outside heat insulation layer adjacent to an enclosure layer. The enclosure layer encloses a space wherein refrigerated water may be placed. The refrigerated water is maintained in a cool state by its contact with hollow studs that contain liquid butane to act as a heat exchanger.
Unlike the packaging system of the present invention, the container of the Guilhem et al. patent cannot ensure that a temperature sensitive material placed in its cooling chamber will not freeze. Furthermore, the Guilhem et al. parent's container is incapable of maintaining its contents at a range of temperatures from 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) when the ambient air temperatures reach extreme high or low temperatures.
For instance, if the packaging system of the present invention were exposed to freezing ambient air temperature such as by placing the entire packaging system containing the temperature sensitive materials in a freezer with a standard temperature of approximately -20.degree. C. (-4.degree. F.) for up to four (4) hours, the temperature sensitive material within the packaging system of the present invention would remain at a temperature in the range of 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.). It is also true that if the entire packaging system of the present invention were placed in an approximately 38.degree. C. (100.degree. F.) room, vehicle trunk, etc. for up to six (6) hours, the temperature sensitive material within the packaging system of the present invention would remain at a temperature in the range of 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.).
The same is not true of the container taught by the Guilhem et al. patent because the container taught by the Guilhem et al. patent does not have a cooling mechanism which includes a combination of frozen and refrigerated cooling components as does the packaging system of the present invention. Thus, the container taught by the Guilhem et al. patent could not ensure temperature sensitive materials placed inside its overall container would not freeze or become overheated if exposed to an extreme low or high ambient air temperature for several hours.
The Douglas-Hamilton patent discloses a container for cooling, preserving and safely transporting a biological specimen. The container taught by the Douglas-Hamilton patent includes a thermally insulated overall container having as its contents a container for ice, a container for specimen, i.e., a thermally insulated metal cup, and a thermally insulating sheet interposed between the specimen container and the ice.
The Douglas-Hamilton patent also discloses a method of packing biological specimen just after it is obtained. The method includes the method steps of packing the recently acquired biological specimens into a specimen container, placing a thermally insulating sheet between ice and the specimen container and placing the specimen container near the ice place within an overall insulating container. The method also includes choosing thermal constants of the container to cool down the specimens at an optimum cooling rate and to achieve an optimum steady state temperature for the specimens.
Unlike the packaging system of the present invention, the container taught by the Douglas-Hamilton patent cannot ensure that temperature sensitive materials placed inside the specimen container will be maintained at a temperature in the range of 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) if the ambient air temperature outside the package reaches extreme high or low temperatures for several hours.
It is an object of the present invention to provide a packaging system for transporting temperature sensitive materials from one place to another which is made up of a secondary insulating container which includes a corrugated fiberboard carton, a plastic liner bag, and rigid foam insulating wall liners in order to house a combination of two frozen refrigerant packs and two refrigerated refrigerant packs around a primary flexible foam-lined insulating container in which the temperature sensitive materials are placed in order to maintain the temperature sensitive materials at a temperature in the range of 2.degree. C. to 10.degree. C. (36.degree. F. to 50.degree. F.) even if the ambient air temperature outside the package reaches extreme high or low temperatures for several hours.
It is a further object of the present invention to provide a packaging system for transporting temperature sensitive materials from one place to another wherein the entire carton and its contents may be exposed to somewhat low extreme ambient air temperatures, for example, such as if placed in a standard freezer at a temperature of approximately -20.degree. C. (-4.degree. F.), for up to four hours without freezing of the temperature sensitive materials within the carton.
It is a further object of the present invention to provide a packaging system for transporting temperature sensitive materials from one place to another wherein the entire carton and its contents may be exposed to somewhat high extreme ambient air temperatures, for example, such as if placed in a 37.8.degree. C. (100.degree. F.) room, vehicle trunk, etc., for up to six hours without damage due to overheating of the temperature sensitive materials within the carton.